Railway signaling system



0kt. 4, 1938. I G. R. PFLASTERER 2,132,125-

RAILWAY SIGNALING SYSTEM Filed June 22, 1937 3 Sheets-Sheet l a; g g; Sw m If m 11 gs;

4F 3% B Q g R N 5 a w INVENTOR a 3 $661 91. 1 v v HLS ATTORNEY Oct. 4,1938.

G. R. PFLASTERER 2,132,125

RAILWAY SIGNALING SYSTEM Filed June 22, 1957 3 Sheets-Sheet 2 x s &Q IfQ) T \0 g 1;; E N $.33 wt Mb Q 1 INVENTOR I George 1?. Pf (en en M BY,HLS ATTORNEY Oct, 4-, 1938. e. R. PFLASTERER 2,132,125

RAILWAY SIGNALING SYSTEM Filed June 22, 1937 3 Sheets-Sheet 5 \NUQQUMEINVENTOR Zasze ezq George 12.

HIS ATTORNEY Patented Oct. 4, 1938 PATENT OFFICE 2,132,125 RAILWAYSIGNALING SYSTEM George R. Pflasterer, Swissvale, Pa., assignor tov TheUnion Switch & Signal Company, Swiss,- vale, Pa., a corporation ofPennsylvania Application June 22, 1937, Serial No. 149,655

9 Claims.

My invention relates to railway signaling systems of the type involvinglight signals wherein the signals each comprise a plurality of lamps andwherein when one lamp of a signal becomes burned out another lamp ofthat signal will become lighted to display a more restrictiveindication.

The apparatus provided by this invention is an improvement on theapparatus shown and claimed in the application of Leon D. Dickinson andDavid C. Bettison, for Light-out protection circuit,'Serial No. 225,372,filed August 17, 1938.

One object of my invention is to provide a signaling system wherein adistinctive permissive indication is displayed at the entrance to anoccupied block so that a train may enter such block without stopping andwherein a stop indication is displayed if the permissive indication isnot displayed when it should be. p

Other objects of my invention will become apparent as the specificationprogresses.

I shall describe several forms of railway signaling systems embodying myinvention, and shall then point out the novel features thereof inclaims,

In the accompanying drawings, Figs. 1A and 1B are diagrammatic viewswhich, when placed end to end in the order named, illustrate one form ofapparatus embodying my invention.

Figs. 2 and 3 are diagrammatic views each illustrating a differentmodification of a portion of the apparatus shown in Fig. 1A, and eachalso embodying my invention.

Similar reference characters refer to similar parts in each of theseveral views.

Referring first to Figs. 1A and 1B, the reference characters 5 and 6designate the rails of a stretch of railway track over which trafficnormally moves in the direction indicated by the arrows. The rails 5 and5 are divided by insulated joints 1 into a plurality of sections ofwhich sections W-X and X-Y are representative sections. Each section isfurther divided, as here shown, into two subsections IT, 2T, 3T, etc.Each subsection is provided with a track battery 8 connected across therails at one end of the subsection and with a track relay, designated bythe reference character TR with arprefix the same as the prefix in thereference character for the associated subsection, connected across therails at the other end of the subsection.

Located adjacent the entrance end of each track section is a signaldesignated by a suitable distinguishing reference character. As hereshown, each signal includes a proceed lamp G capable of displaying agreen light, a caution lamp Y capable of displaying a yellow light, anda stop lamp R capable of displaying a redlight.

Each signal is provided with a polarized signal control relay,preferably of the retained neutral type, and designated by the referencecharacter HD with a prefix the same as the reference character of theassociated signal.

Each signal control relay HD is connected'to a pair of lineconductors'each including a front contact of each of the associatedtrack relays and each extending to the signal next in advance. As willbe explained more in detail hereinafter, each pair of line conductors isreversibly governed by the apparatus associated with the signal next inadvance.

Each signal is provided with two direct current lightout relaysdesignated by the reference characters GLO and YLO each with a prefixthe same as the reference character of the associated signal. Each relayGLO is provided with two windings I 3 and I4 and each relay YLO isprovided with two windings I5 and I6.

Each signal is provided with an auxiliary relay designated by thereference character F with a prefix the same as the reference characterof the associated signal. Each relay F is provided with a' controlcircuit which includes its own back contact so that whenever the controlcircuit is energized the associated relay F becomes periodically pickedup and released. As will be explained more in detail hereinafter, therelays F are utilized at times to open and close periodically thelighting circuit for the caution lamp Y of the associated signal so thatthat signal will display a flashing aspect.

Each signal is provided with a suitable source of direct current andwith a suitable source of alternating current, the terminals of whichare designated'by the reference characters B and C, and BX and CK,respectively.

For governing the character of the current supplied to the signal lamps,each signal is pro- Vided with an alternating current power-01f relaydesignated by the reference character P0 with a prefix the same as thereference character of the associated signal. That is, the current forlighting the signal lamps is supplied from terminals BX and CX or B andC according as the associated relay PO is picked up or released,respectively. Since the relays P0 are directly connected to theterminals BX and CK, it follows that the lamps of the associated signalare normally lighted by alternating current but will Each of the signalsand associated apparatus is controlled by the associated relay HD in thefollowing manner: When relay HD is deenergized (see signal ll), relay HFis periodically energized by a circuit which passes over a path fromterminal B through back point of contact.

l8 of relay lIHD, back contact l9 of relay HF, and relay HF to terminalC, with the result that Y relay HF is repeatedly picked up and released.

- pied.

Consequently, lamp Y is periodically energized to cause signal Y todisplay a flashing yellow light to indicate proceed with caution--blockoccuthrough front point of contact of relay HPO,

back point of contact 2| of 'rel'ay"'I!I-ID, front contact 22 of 'relayIIF', winding l5 of relay HYLO, lamp Y'Of signal H, and front point ofcontact 23 of relay PO to terminal. C. Asymmetric unit 24 is connectedaround winding IE to by-pass each half wave of alternating current sothat relay'l IYLO; although of the direct current type, will beeffectively energized by alternating current as well as 'by directcurrent. Winding l3 of relay HGLO and winding iii-of relay IIYLOareprovided in a similar manner with asymmetric units 25 and26,respectively, for the same purpose. When relay IIHD is released, windingM of relay I IGLO is also energizedvby a circuit which passes fromterminal B through back point of contact 21 of relay IIHD and winding 14of relay l IGLO to terminal C so that this relay is maintained in itspicked up condition.

When relay HD is energized in the reverse direction (seesignal'ill), acircuit is established for steadily energizinglamp Y of that signal to Icause the signal to display a steady 'yellow light to indicate proceedwith 'cautionone block clear. This circuit may be tracedover a pathwhich passes from terminal BX through front point of. contact 28 ofrelay l BPO, front point of contact 29 of relay IUHD, reverse polarcontact 30- 3i of relay IOHD, winding i5 of relay HJYLO,

lamp Y of signal [0, and front pointof contactv 32 of relay IOPOtoterminal BX. Relay IOYLO is, of course, in'its picked'up conditionbecause.

winding I5 is included in the circuit for lamp'Y,

and relay IBGLO is also in its picked up condition because its winding[4 is energized by a circuit which passes over'a path from terminal Bthrough front point of contact'33 of relay HJHD, reverse polar contact34-35 of relay HIHD, and winding M of relay IOGLO to terminal C.

When relay HD is energized in the'normal direction (see signal 9), acircuitis established for energizing lamp G of signal 9 so that thesignal is displaying a green light to indicate proceed at normal.speedtwp blocks clear. This circuit may be traced over apath'whichpasses from terminal BX through front point of "contact '36 of relaySPO, front point of contact 31 of relayQHD, normal polar contact 3938 ofrelay 9HD, windingl3 of relay 9GLO, lamp Winding I3 is included in thecircuit for lamp- G, and relay 9YLO is maintained in'its picked upcondition because its winding [6 is energized The circuit for lamp -Ymay be traced" 'over a path which passes from terminal. BX

by a circuit which passes over a path from terminal BX through frontpoint of contact 36 of ing i6 of relay SYLO, and front point of con-1tact 39 of relay'9PO to terminal CX.

A train K, here shown diagrammatically, is

occupying the section immediately to the right of location Y sothatrelay iiI-ID is deenergized with the result that relay illHD isenergized in the reverse direction by a circuit which passes.

over a path from terminal B at signal I I through back point of contactM of relay ill-ID, front contact 42 of. relay QTR, front contact 43 ofrelay 3TR, relay IUI-ID, front contact M of relay 3TB, front contact 45of relay 4TH, and back point of contact 46 of relay ill-ID to terminal Cat signal ll.

Relays IQHD and iDYLO being both energized,

relay QHD is energized in the normal direction by a circuit which passesover a path from terminal B at signal 'I 9 through front point of conetact 41 of relay IQYLO, front point of contact Q8 of relay IOHD, frontcontact 49 of relay 2TB, front contact 59 of relay iTR, relay 9HD, frontcontact 5| of relay ITR, front contact 52 of relay ZTR, front point ofcontact 53 of relay i 9I-ID,'and front point of contact 54 of relayIOYLOto terminal 0 at signal i0.

' Since both relay 9HD and relay 9YLO are energized,'the line circuit tothe rear of location W is energized in the'normaldirection over front 1points of contacts 55 and 56 of relay SYLO and front points of contacts51 and 58 of relay 9HD so that the relay I-ID (not shown) controlled bythat line circuit is in condition to'cause its signal (not shown) todisplay the normal proceed indication. g

I In the event that the lamp Y at signal H becomes burned out, energywill be disconnected.

from winding l5 of relay HYLO so that this relay will become released toestablish a circuit for the lamp R of signal H to cause that signal todisplay a red light to indicate stop. The circuit for lamp R may betraced over a path which passes from terminal BX through front point ofcontact 20 of relay IIPO, back contactf 60 of relay I IYLO, reactor 61of signal I lamp R of signal Ii, and front point of contact 23 of relayPO to terminal CX. The reactor 6! is of substantially the samereactanceas windings l3 and I5 of relays HGLO' and IIYLO, respectively,and is provided to equalize the voltage applied to lamp R with thatapplied to lamps G and Y. -In a similar manner, if the lamp Y at signalIt) becomes burned out, relay IOYLO will become released to close acircuit for lamp R of. signal i0 over back contact 62 of vrelay IUYLO sothat signal it will be caused to display the stop indication. 1 a

If the lamp G at signal 9 becomes burned out, relay 9GLO will becomereleased to establish a circuit for lamp Ybecause energy will be discon-'nected from winding I3 of relay 9GLO. This circuit may be traced over apath which passes from terminal BX through front point of contact 36 ofrelay 9P0, front point of contact 31 of relay 9HD, normal polar contact30'38 of relay 9HD, back point of contact 40 of relay-SGLO, winding 15of relay 9YLO, lamp Y of signal 9, and front point of contact 39 ofrelay SP0 to terminal CX. In the event that lamp Y of signal 9 thenbecomes burned out to release relay 9YLO,

lamp Rof signal 9 will become lighted over back contact 63 of relay9YLO.

It will be noted that whenever any of the relays YLO becomes released,the line circuit to the rear becomes energized in the "reverse'direction if such line circuit is not already so energized. For example,if relay IOYLO becomes released, thedirection of energization of theline conductors for section W--X will be changed to the reversedirection over the back points of contacts 41 and 54 of relay illYLO sothat signal 9 will be caused to display a caution indication.

Thus, it will be seen that if the green lamp of a signal is burned outwhen it should be lighted, that signal will be caused to display acaution indication, and if the yellow lamp of a signal is burnedout'when it should be lighted, that signal will be caused to display astop indication and the signal next in rear will becaused to display acaution indication.

The retained neutral characteristic of the polarized relays HD preventstumble-down of the signal control circuits to the rear during polechanging periods. For example, when the train K vacates the section tothe right of locationY so that the energization of relay [OI-ID ischanged from the reverse direction to the normal direction, the frontpoints of neutral contacts48 and 53 of relay lllHD do not become openedand, consequently, the energization 'of the line circuit for sectionW--X is not disturbed.

The slow releasing characteristic of relays GLO and YLO prevents therelease of these relays when energy is transferred from one winding toanother. For example, when the direction of energization of relay IBI-IDis changed so that energy is disconnected from winding l3 and applied towinding M of relay lllGLO, this relay, due to its slow acting feature,does not become released. The slow' releasing characteristic of therelays YLO also prevents the release of these relays when the associatedwinding I5 is being periodically energized such, for example, as occurswhen the apparatus is in the condition as shown in Fig-1B.

Referring next to Fig. 2, it will be understood that although I haveshown only one signal and associated apparatus, such signal andapparatus when connected in a system will function in a manner somewhatsimilar to that described for the apparatus shown in Figs. 1A and 1B.The principal difference in the two schemes is in the character of theindications displayed by the signal. In the present figure, the signalwill display a green light to indicate proceed at normal speedtwo blocksclear, a green light over a yellow light to indicate proceed withcautionone block clear, a yellow light to indicate proceed withcautionblock occupied, and a red light to indicate stop. I 7

When relay HD is energized in the normal direction as shown in thedrawings, a circuit is established for winding N5 of relay YLO whichcircuit may be traced over a path which passes from terminal BX throughfront point of contact 65 of relay PO, front contact 66 of relay HD,normal polar contact 6'L- 68 of relay I-ID, winding l 6 of relay YLO,and front point of contact 64 of relay PO to terminal CX.

Relay HD and relay YLO both being energized, a circuit is establishedfor la'mpG which circuit may be traced over a path which passes fromterminal BX through front point of contact 65 of relay PO, front pointof contact 10 of relay YLO, reactor 1 l, front contact 12 of relay HD,lamp G, and front point of contact 69 of relay PO to terminal CX.

When relay HD becomes energized in the re-' verse direction, a circuitwill be established for lamp Y which circuit passes over a path fromterminal BX through front point of contact 65 of relay PO, front pointof contact 13 of relay HD,'reverse polar contact 14-45 of relay HD,winding l 5 of relay YLO, lamp Y, and front point of contact 69 of relayPO to terminal CX. Although energy will be disconnected from winding [6of relay YLO by the opening of normal polar contact 61-68 of relay HD,relay YLO will remain in its picked up condition to maintain thepreviously traced circuit for lamp G because winding l5 of relay YLO isconnected in series with lamp Y.

When relay HD becomes deenergized, another circuit will be estabilshedfor lamp Y and the circuit for lamp G will become opened. This circuitfor lamp Y may be traced over a path which passes from terminal BXthrough front point of contact 65 of relay PO, back point of contact 13of relay HD, winding {5 of relay YLO, lamp Y, and front point of contact69 of relay PO to terminal CX.

In the event that lamp Y should become burned out, energy will bedisconnected from winding l5 of relay YLO so that a circuit would beclosed for lighting lamp R. This circuit passes over a path fromterminal BX through front point of contact 65 of relay PO, back point ofcontact 10 of relay YLO, reactor 16, lampR, and front point of contact69 of relay PO' to terminal C.

The line circuit to the rear is controlled ina manner similar to thatdescribed for the line circuit shown in Figs. lAand 1B. That is, whenboth relays HD and YLO are energized, the rear line circuit is suppliedwith energy in the normal direction, but when either relay HD or relayYLO is deenergized, the rear line circuit is supplied with energy in thereverse direction.

Referring now to Fig. 3, it will be understood that the single signaland associated apparatus will, when connected in a system, function in amanner somewhat similar to that described for the apparatus shown inFigs. 1A and 1B. The principal difference between the two schemes is inthe character of the indications displayed by the signal. In the presentfigure, the signal displays a green light over a green light to indicateproceed at normal speedtwo blocks clear,

a single green light to indicate proceed with caution-one block clear,a' yellow light 'to indicate proceed with cautionblock occupied, and ared light to indicate stop.

When relay HD is energized in the normal direction, as shown in thedrawings, circuits are established for both the upper and lower signallamps G. The circuit for upper lamp G may be traced over a path fromterminal BX through front point of contact 18 of relay PO, front pointof contact 19 of relay HD, winding l3 of relay GLO, upper lamp G, andfront point of contact of relay PO to terminal CX. The circuit for lowerlamp G may be traced over a path from terminal BX through front point ofcontact 18 of relay PO, frontpoint of contact 8| of relay HD, normalpolar contact 82-433 of relay I-ID, reactor 8 lower lamp G, and frontpoint of contactflil of relay PO to terminal CX.

Relay GLO is maintained in its picked up condition because winding l3isconnected in series with upper lamp G and relay YLO is maintained in itspicked up condition because winding I5 is energized by a circuit whichmay be traced over apathgpassing from terminal BX through front point ofcontact 18 of relay PO, front point of contact 8l of relay HD, windingl5 of relay YLO,

and front point of contact 80 of relay PO to terminal CX. f r

'When relay I-ID becomes energized in the reverse direction, the circuitfor lower lamp G will be opened at normal polar contact 8283 of relay.I-ID, but the previously traced circuits for both the upper lamp G andwinding l5 of relay YLO will remain closed. Inthe event that theupper-lamp G becomes burned out, so that energy is disconnected fromwinding 13 of relay GLO, another circuit for lower lamp G will becomeestablished so that the signal will continue to display a single greenlight. This circuit passes over a path fromterminal BX through frontpoint of contact 13 of relay PO, front point of contact '59 of relayI-ID, back contact 85 of relay GLO, reactor 84, lower lamp G, and frontpoint of contact 80 of 'relay PO to terminalCX. When relay HD becomesdeenergized, a circuit will be established for lamp Y which circuitpasses over a path. from terminal BXthrough front point of contact 18 ofrelay PO, back point of. contact SI. of relay HD, winding 16 of relay.

YLO, lamp Y, and front point of contact'88 of relay'PO .toterminal CX.Relay YLO will be maintained in its picked up condition because windingI6 is included in the circuit for lamp Y and relay GLO will bemaintainedin its picked 1 up condition because winding M will beenergized by a circuit which passes from terminal BX through front pointof contact 18 of relay PO, backpoint of contact 19 of relay HD, windingM of. relay GLO, and front point of contact 8!] of relayPO to terminalCX.

In the event that lamp Y becomes burned out, energy will be disconnectedfrom winding H3 so that relay YLO will be released to establish acircuit for lamp R. to cause'the signal to display a red light. Thiscircuit maybe traced over a path which passes from'terminal BX throughfront point of contact 18 of relay PO, back contact 86 of relay YLO,reactor 81, lamp R, and

front point of contact 80 of relay PO to terminal CX. I

I The line circuit to the rear isreversibly governed by the relays HDand YLO in a manner similar to that described for the apparatus shown inthe other figures, and it is believed that this will be obvious from thedrawings without further explanation.

From theforegoing description of the apparatus embodying my invention,it will be seen that I have provided a signal system wherein adistinctive permissive aspect is displayed at the entrance to anoccupied block so that a following train may enter such block withoutstopping and wherein a stop aspect is displayed if the permissive aspectis not displayed when it should be. Furthermora'I have provided controlcircuits for the signal next in rear which circuits function in such amanner that the rear signal will be caused to display a restrictiveaspect whenever the signal next in advance is displaying its stop aspectregardless of the condition of the 7 signal control signal; V

Although I have herein shown and described relay associated with suchadvance only a few forms of railway signaling systems embodying myinvention,it is understood that various changes and modifications .maybe made therein within the scopeof the appended claims asecond lamp, acircuit for energizing said first lamp when said section is occupied, arelayhaving two windings, one winding of said relay being included insaid circuit, means for energizing the other winding of said relay whensaidsecti-on is unoccupied, and'acircuit for said secondlamp including aback contact of said relay.

2. Incombination, a section of railway-track, a signal for said sectionincluding a first lamp and a second lamp, a relay'having two windings,means for energizing one winding of said relay when said section isunoccupied,me ans for energizing said first lamp when said section iscocupied and .for. simultaneously energizing the other winding of saidrelay provided the filament of said first lamp is then intact,'andmeans, for energizing said second lamp if and only if said relay isreleased.

3. Incombinatioh, a section of railway track, a signal for said section,a control relay for con trolling. said signal, means'for energizing orde energizing said relay according as said section is 'if said auxiliaryrelay becomesdeenergized.

4. In combinatioma plurality of successive sections of railway track, asignal for each section each including a first lamp, a second lamp and athird lamp, a relay for eachsection each including two windings, meansfor each section for simultaneously energizing the associated first lampand one winding of the associated relay when that section is unoccupied,a circuit for each section including the associatedsecond lamp and theother winding of the associated relay in series, means for each sectionfor energizing-the associated circuit when that section is occupied, anda means for each section for energizing the associated third lamp whenthe associated relay is deenergized. a

v 5. In combination, a pluralityof successive sections of railway track,a signal for each section each including a first lamp, a second lamp anda third lamp, a relay for each section each including two windings,means for each section for simultaneously energizing the associatedfirst lamp and onewinding of the associated relay when that section isunoccupied, a; circuit for each section including the. associated secondlamp and the otherwinding of the associated relay, in series, means foreach section for energizing the associated circuit when that section isoccupied, means for each section for energizing. the associated thirdlamp when the associated relay is,

deenergized, and means for each section governed by the associated relayfor at times governlamp, a caution lamp and a stop lamp, a polarizedsignal control relay which becomes deenergized when said section isoccupied but which is energized in the normal or reverse direction inaccordance with trafiic conditions in advance when said section isunoccupied, a first lightout relay having two windings, a secondlightout relay also having two windings, a circuit for said proceed lampincluding a front contact and a normal polar contact of said controlrelay in series with one winding of said first lightout relay, a circuitfor one winding of said second lightout relay including a front contactof said first lightout relay, a circuit for supplying current to saidcaution lamp in the event of failure of said proceed lamp, said circuitincluding a front contact and a normal polar contact of said controlrelay as well as a back contact of said first lightout relay in serieswith the other winding of said second lightout relay, another circuitfor said caution lamp including a front contact and a reverse polarcontact of said control relay in series with said other winding of thesecond lightout relay, still another circuit for said caution lampincluding a back contact of said control relay in series with said otherwinding of said second lightout relay, means including a back contact ofsaid control relay for periodically interrupting said last mentionedcircuit, means for energizing the other winding of said first lightoutrelay when said control relay is deenergized as well as when saidcontrol relay is energized in the reverse direction, and a circuit forsaid stop lamp including a back contact of said second lightout relay.

'7. In combination, a section of railway track, a signal for saidsection including a proceed lamp, a caution lamp and a stop lamp, apolarized signal control relay which becomes deenergized when saidsection is occupied and which becomes energized in the normal or reversedirection in accordance with traffic conditions in advance when saidsection is unoccupied, a lightout relay having two windings, a circuitfor one winding of said lightout relay including a front contact and anormal polar contact of said control relay, a circuit for said proceedlamp including a front contact of said lightout relay and a frontcontact of said control relay, a circuit for said caution lamp includinga front contact and a reverse polar contact of said control relay inseries with the other winding of said lightout relay, another circuitfor said caution lamp including a back contact of said control relay inseries with said other winding of the lightout relay, and a circuit forsaid stop lamp including a back contact of said lightout relay.

8. In combination, a section of railway track, a signal for said sectionincluding a, first and a second proceed lamp as well as a caution andstop lamp, a polarized signal control relay which becomes deencrgizedwhen said section is occupied and which becomes energized in the normalor reverse direction in accordance with traffic conditions in advancewhen said section is unoccu pied, a first lightout relay having twowindings, a second lightout relay also having two Windings, a circuitfor said first proceed lamp including a front contact of said controlrelay in series with one winding of said first lightout relay, a circuitfor said second proceed lamp including a back contact of said firstlightout relay and a front contact of said control relay, anothercircuit for said second proceed lamp including a front contact and anormal polar contact of said control relay, a circuit for said cautionlamp including a back contact of said control relay in series with onewinding of said second lightout relay, a circuit for said stop lampincluding a back contact of said second lightout relay, and means forenergizing the other windings of said first and second lightout relayswhen said control relay is deenergized and energized respectively.

9. In combination, a section of railway track, a signal for said sectionincluding a first and a second as well as a third and a fourth lamp,means effective under certain trafiic conditions in advance of thesignal for lighting said first and second lamps to cause said signal todisplay an indication, means effective under other certain trafficconditions in advance of the signal to light only said second lamp tocause said signal to display another indication, means eifective tolight said first lamp if said second lamp is then burned out, meanseffective to light said third lamp when said section is occupied tocause said signal to display a difierent indication, and means efiectiveto light said fourth lamp if said third lamp is then burned out to causesaid signal to display still a different indication.

GEORGE R. PFLASTERER.

